Device for guiding thin bands



Nov. 4, 1952 J. A. HARINGX 2,616,

DEVICE FOR GUIDING THIN BANDS Filed April 29, 1946 ATTORNfY Patented Nov. 4, 1952 2,616,690 DEVICEFOR GUIDING THIN BANDS Johannes Adrianus Haringx, Eindhoven, Netherlands, assignor to Trust Company, Hartford,

Application April 29,

2 Claims.

For impelling thin bands having a thickness of, for example, several times ten micron, for instance films made from partly or entirely regenerated cellulose for recording or reproducing images and/or sound records, it has been found to be necessary to abstain from the usual means for guiding the bands in a lateral direction, for example rollers having rotating or non-rotating flanges or other resilient guide members between which the band is travelling. In fact, the band material having the said thickness does not react upon such a guiding, so that damaging and frequently even rupture of the bands is unavoidable. This evil can be cured by making use of fixed stops which, in the case of a suitable control, are engaged by one side of the band of its own accord. Such a control may, for example, be ensured by driving and/or braking the band in the proximity of the stop unsymmetrically with respect to the longitudinal direction. In this case a couple is exerted on the band in its plane with the result that the band tends to deviate laterally inthe manner set out above.

When using a member to constitute the stop, by which the band is guided only at the side, the stop can practically only be used where the path of the band is curved, for example where it passes over a cylindrical driving or guide roller. With a View to the small thickness of the band it has an adequate, artificial rigidity only in situ, to prevent the band from curling at its edge. Where the'path of the band is straight it isnot advisable to use such a stop.

The object of the invention is to procure means which enable to arrange stops also along the straight parts of the band, which the band engages of its own accord during the transport without curling of the edge in that area. For this purpose the stop in the device according to the invention constitutes the bottom of a guttershaped member, the edge of the band passing between the side walls thereof.

It is advisable to fasten the gutter walls in a lateral direction rigidly with respect to the stop, since a resilient arrangement, for example, entails the risk that the edge of the band is jammed during its travel and is consequently damaged in the space between the stop and the resilient side walls. The rigid fastening may, for example, be obtained by making the gutter-shaped member in one piece. It is, however, preferable to construct the member from separate plates which are clamped together. This has the advantage that the stop can easily be given a definite curvature in a longitudinal direction of the film, which is desirable to avoid the diificulty that, in the case Hartford National Bank and Conn, as trustee 1946, Serial No. 665,666 In Belgium February 8, 1945 Section 1, Public Law 690, August 8, 1946 Patent expires February 8, 1965 of a straight stop, it must be adjusted exactly parallel with the edge of the band. Another advantage consists in the avoidance of rounded edges of the stop at the transition to the gutter walls, owing to which the surface of the stop engaged by the edge of the band, is curved and an incorrect guiding of the band may occur. In addition, this construction permits in a simple manner an accurate adjustment of the spacing between the gutter walls by a suitable choice of the thickness of the plate located between the gutter walls. In order that no trouble is experienced from joints, if any, in the band when it passes through this member, the inner walls of the gutter are located at a distance slightly exceeding twice the thickness of the band. With a film having a thickness of 40 microns the distance may, for example, be 0.1 mm.

If it is desirable that also the central part of the band should be kept fiat, the gutter walls may be so constructed as to embrace the band throughout its width. This is, however, not necessary if other means are available for this purpose, for example, when using the device according to the invention for cinematographic films at the picture gate, where the conventional resilient construction of the picture gate keeps the band sufficiently flat. In this case it sufiices that the film part is embraced which extends from the edge to the picture strip which yields the additional advantage that no trouble is experienced from the stop during exposure or reproduction. In the case of a 16 mm. small film it is, for example, suiiicient if a strip having a width of 1.5 mm. is gripped. One of the gutter walls may, as an alternative, be longer than the other, for example when it forms part of the fixed wall of the picture gate. If the side of the other, shorter wall facing the film be rounded at its edge, the film can readily be introduced into the guide member.

In order that the invention may be clearly understood and readily carried into effect, it will now be explained with reference to the accompanying drawing, in which one form of construction is shown by way of example.

Figs. 1 and 2 show diagrammatically how a moving band can be guided to ensure that it engages, of its own accord and with one of its sides, a fixed stop during its travel.

Fig. 3 is a cross sectional view and Fig. 4 is a plan view of the device according to the invention such as can be used for guiding a pictorial film, for example of regenerated cellulose, having a width of 16 mm. and a thickness of 40 microns.

In Figs. 1 and 2 the reference numeral i desighates the unperforated film band which passes over a smooth roller In the drawing this roller is a loose guide roller which follows the movement of the film. Unsymmetrically with respect to the longtiudinal axis of the filmare provided two felt plates 9 and i between which moves the film. These plates can be more or less pressed together, which pressure is variable at will by means of a device (not shown). The friction owing to the contact between these plates and the film produces a force which applies asymmetrically with respect to the longitudinal axis of the film, with the result that a couple is exerted on the film in its plane so that the film engages, of its own accord, the stop 5. In the present case the stop is represented by a fiat plate and consequently does not pertain to the device according to the invention. This is represented in Figs. 3 and In these figures the film 5 is provided with a row of pictures 1. During its travel, which may take place as shown in Figs. 1 and 2, the film engages a stop 8 which is rounded in the direction of length of the film and constitutes, according to the invention, the bottom of a gutter-shaped member, whose sidewalls are formed by plates 9 and 55 which, similarly to the stop 8, are preferably made from a wear-resisting material, e. g. spring steel. Between the sidewalls the film is guided over a width of 1.5 mm. By means of two screws 8 l the sidewalls are rigidly fastened to the stop 6 and are spaced apart by a distance slightly exceeding twice the thickness of the film so that any joints can readily pass the gutter. When film parts without joints are passing the film will move through the gutter with some amount of play. This is, however, not objectionable because this play is small with respect to the part of the film width which is adjoined by the gutter walls and since by the rigid clamping together of the sidewalls and the stop there is no risk of the edge of the film being jammed between the sidewalls and the stop, as a result of the said play.

In the form of construction shown byjway of example the sidewall 59 forms part of the picture gate i2 comprising the aperture it through which the projection light beam falls on the film. That side of the shorter gutter wall, which faces the film, is rounded at its end i l to facilitate the introduction of the film:

What I claim is:

1. A device for guiding a thin band moving along in a fiat plane which comprises a driving means for said band, a fixed stop means adjacent one edge of the moving band, said stop means having a channel-shaped portion formed by side portions extending over the side of the band and a bottom surface rigidly secured to said side portions and adapted to be engaged by the aforesaid edge of the band, and brake means for applying a braking action to the band to produce a force urging the band against said bottom surface, said braking means being located between the center line of the film and the edge opposite to that adjacent to which the stop means are located, said brake means also being displaced from said stop means along the longitudinal axis of the band and on the side of the stop means remote from the driving means.

2. A device for guiding a thin band moving along in a fiat plane which comprises a driving means for said band, a fixed stop means adjacent one edge of the moving band, said fixed stop having a channel shaped portion formed by side portions spaced apart a distance slightly exceeding twice the thickness of the band and extending over the side of the band and a bottom surface whose edge is rounded in the plane of the direction of the longitudinal movement of the band, said bottom surface being rigidly secured to said side portions, and brake means for applying a braking action to the band to produce a force urging the band against said rounded bottom surface, said braking means being located between the center line of the film and the edge opposite to that adjacent to which the stop means are located, said brake means also being displaced from said stop means along the longitudinal axis of the band and on the side of the stop means remote from the driving means.

JOHANNES ADRIANUS HARINGX.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1, 622, 836 Moon Mar. 29, 1927 1, 680, 190 Wikle Aug. 7, 1928 2, 012, Kellogg Aug. 20, 1935 2, 082, 799 Hetherington June 8, 1937 2, 102, 895 I-Iasbrouck Dec. 21, 1937 2, 142, 606 Debrie Jan. 3, 1939 2, 190, 413 Davidson Feb. 13, 1940 2, 253,258 Widmer Aug. 19, 1941 2, 464, 173 Broadmeyer Mar. 8, 1949 

